I like a good digression wherein we get a random character's perspective for just one chapter. They are usually not central to the main narrative, but it's like they happened to find themselves in some circumstances that directly or indirectly influence the main story.

For example, one chapter in the middle of The Hunchback of Notre Dame is entitled "History Of A Leavened Cake Of Maize", and it introduces us to a boy and his family who are passing through around where the story takes place and who basically give us some exposition about a secondary character from the main plot. Of course, we also get to know a little about their dynamic and personalities. They never return again.

A perhaps slightly less illustrative example is in "Nine Perfect Strangers", where the story is told from the perspective of guests who are staying at a resort and some employees. One of the guests is a writer and is mortified after a book critic had some not-very-nice things to say about her latest effort. This book critic is only one of the author's problems, and she is mentioned a few times, only once by name. When all the characters are getting chapters near the end devoted to explaning what happened to them after the events of the main story, out of nowhere we get a(n extremely short) chapter from the critic's perspective and it's genuinely one of the funniest bits of literature I've ever read.